The near ultraviolet (NUV) portion of sunlight having photon energy between 3.1 eV to 4.13 eV is particularly detrimental to polymers. These energetic phonons dissociate the carbon-hydrogen bonds in organic materials via a process known as photo-degradation. Since photo-degradation generally involves sunlight, thermal oxidation caused by near infrared (NIR) light can and does take place in parallel, causing catastrophic failure of the coating system within a few days or weeks if exposed to direct sunlight without any protection.1,2 Even durable materials such as polyester, silicone-modified polyester, and polyvinylidene fluoride are prone to chalking due to photo-degradation.3,4 
In the coating industry, one strategy for extending polymer lifetime is to add inorganic ultraviolet (UV) absorbers, such as carbon black and titanium dioxide, to a coating, paint, etc. However, the addition of carbon black and/or titanium oxide typically results in a compromised appearance of the coating.
In a somewhat unrelated field, the same wavelength range responsible for photo-degradation also plays an important role for biological activities of insects and birds.5-8 Light signals based on reflections from exposed animal body surfaces such as a feather, skin, etc., and having a wavelength range between 340-400 nanometers (nm), are widely used as a means of animal communication in mate attraction,9 dominance10 and orientation within a group.11 In addition, UV reflectance may be a condition dependent indicator of male quality because structural colors are unusually good indicators of feather age or feather quality.12, 13 Birds and insects have at least four types of cone visual pigments that absorb light in the NUV range14 and literature on this subject has concluded that due to the NUV vision exhibited by birds, turbine blades coated with NUV-reflective paint could potentially decrease the number of annual avian collisions.15 
Regarding insects, NUV reflective plastic mulches were developed in the early 1990's and used to successfully to reduce the incidence of aphidborne virus diseases in squash and other crops,16 to delay colonization by B. argentifolii and reduce the incidence of squash silverleaf.17 Reflecton of NUV light by these mulches confuses and repels incoming alate aphids and adult whiteflies, thereby reducing their incidence of alighting on plants.18,19 
In addition to these “unconventional” applications, NUV-reflective coatings are desirable for many optical devices such as laser, optical filters, microcavity mirrors, or distributed Bragg mirrors.20-23 
Brilliant colors in the natural world originating from fish, butterflies and/or birds follow the principal of “structural color” through interference of light reflected from a periodic biological nanostructure,28 structural colors easily reflecting up to 100% of incident light compared to 50-60% for conventional colors based on molecular absorption. In addition, recent discoveries in photonic crystals (PC) have generated significant interest into manipulating the photonic band gap (PGB) in order to gain control over electromagnetic radiation within the PGB.24-26 As such, dimensional (1D) PCs have proven particularly promising due to their simple design for potential commercial applications, and when designed to reflect light in a narrow range in the visible region, can become or exhibit a structural color. As such, nature's ability to create structural colors has led to 1D PCs that produce structural colors, the 1D PCs consisting of alternating stacks of low and high refractive index materials.27-30 
Typical quarter-wave Bragg reflectors can be made from alternating stacks of low and high refractive index materials with equal optical thicknesses of these stacks, that is nLdL=nHdH=λ0/4 where λ0 is an operating free-space wavelength and dL, dH and nL, nH are the thicknesses and refractive indices of the low and high refractive index materials, respectively. All layers within such a multilayer structure have a common phase thickness δ=2π nHdH/λ (or δ=2π nLdL/λ) that results in equivalent two-way travel-time delay for light. In addition, since a translation matrix is periodic in 6, multiband mirror behavior will occur at odd multiples of λ0. A quarter-wave reflection design can be represented by AH(LH)N G, where A and G represent air and glass (or substrate), N is the number of stack pairs and L and H represent thicknesses for the low and high refractive index layers.
Methods used most commonly for thin-film deposition include chemical vapor deposition (CVD)31,32 and physical vapor deposition (PVD).33,34 And although these methods provide well-controlled film growth, high cost and size limitations have led to alternative methods being sought. While other methods, such as sol-gel process,35 overcome the limitations of the methods mentioned above, such methods introduce a limitation of uniformity over curved substrates.
The layer-by-layer (LbL) assembly method has been widely used to overcome cost, size and control based limitations. In addition, the LbL method is water based and environmentally friendly with minimum carbon footprint. In recent years, flexibility and control of this approach have been exhibited by depositing alternating polymer-polymer,36 polymer-nanoparticle,37,38 and nanoparticle-nanoparticle39,40 layers that can be stacked using pH and nanoparticle size as controlling parameters through electrostatic interactions.
In summary, UV-reflective coatings are known to be useful and structural colors are known to be aesthetically pleasing. However, heretofore structural colors have not provided appropriate UV-reflection properties. As such, a structural color that also exhibits UV-reflectance would be desirable.